On Fri, Nov 5, 2021 at 8:57 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> Clang warns:
>
> fs/nfs/dir.c:1772:6: error: variable 'error' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized]
> if (fhandle == NULL || fattr == NULL)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/nfs/dir.c:1801:44: note: uninitialized use occurs here
> trace_nfs_lookup_exit(dir, dentry, flags, error);
> ^~~~~
> fs/nfs/dir.c:1772:2: note: remove the 'if' if its condition is always false
> if (fhandle == NULL || fattr == NULL)
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/nfs/dir.c:1772:6: error: variable 'error' is used uninitialized whenever '||' condition is true [-Werror,-Wsometimes-uninitialized]
> if (fhandle == NULL || fattr == NULL)
> ^~~~~~~~~~~~~~~
> fs/nfs/dir.c:1801:44: note: uninitialized use occurs here
> trace_nfs_lookup_exit(dir, dentry, flags, error);
> ^~~~~
> fs/nfs/dir.c:1772:6: note: remove the '||' if its condition is always false
> if (fhandle == NULL || fattr == NULL)
> ^~~~~~~~~~~~~~~~~~
> fs/nfs/dir.c:1754:11: note: initialize the variable 'error' to silence this warning
> int error;
> ^
> = 0
> 2 errors generated.
>
> Add a label to skip the call to trace_nfs_lookup_exit() when the call to
> nfs_alloc_fhandle() or nfs_alloc_fattr_with_label() fails because
> trace_nfs_lookup_enter() has not been called at that point so tracing
> the exit does not make sense.
>
> Fixes: 8d3df1d0387e ("NFS: Remove the label from the nfs4_lookup_res struct")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1498
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> fs/nfs/dir.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
> index 8de99f426183..1c978a7cf730 100644
> --- a/fs/nfs/dir.c
> +++ b/fs/nfs/dir.c
> @@ -1770,7 +1770,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in
> fhandle = nfs_alloc_fhandle();
> fattr = nfs_alloc_fattr_with_label(NFS_SERVER(dir));
> if (fhandle == NULL || fattr == NULL)
> - goto out;
> + goto out_no_trace;
>
> dir_verifier = nfs_save_change_attribute(dir);
> trace_nfs_lookup_enter(dir, dentry, flags);
> @@ -1799,6 +1799,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in
> nfs_set_verifier(dentry, dir_verifier);
> out:
> trace_nfs_lookup_exit(dir, dentry, flags, error);
> +out_no_trace:
> nfs_free_fattr(fattr);
> nfs_free_fhandle(fhandle);
> return res;
>
> base-commit: cb66e0e973daa668dadd43441f877377a1b7b1ff
> --
> 2.34.0.rc0
>
>
--
Thanks,
~Nick Desaulniers
